Hi Developers,
I came across a issue that apex cannot process xlxs, xls but didn't get clear explaination.
Can anyone explain why we cannot process xlsx,xls but can only process CSV and other format?
Thanks

Hi i am new to saleforce, 
I need to dynamically show / hide apex:column  in pageblocktable. I found a code which was working for datatable which uses column index to hide a column but not for pageblock table  because datacolumn index is not applicable in pageblocktable.